by Tom Pelissero, USA TODAY Sports

by Tom Pelissero, USA TODAY Sports

More NFL players are likely to wear sensors that assess head impact in games this season as the league and its players union expand a project proponents hope will help them tackle the concussion issue.

Kevin Guskiewicz, a University of North Carolina researcher who's a member of league and union safety committees, told USA TODAY Sports two companies are "fine-tuning" their head accelerometer devices based on researchers' feedback in anticipation of wider deployment this fall, with expansion to all 32 teams possible as soon as 2015.

"We need a sample of these players across all positions and studying every play type possible," Guskiewicz said by phone Sunday night. "So, that's the next step. Then I hope from there that, if we find (the devices) have utility that could actually help an individual player â?¦ my hope would be that we would go league-wide."

Two NFL teams participated in a pilot project for half of the 2013 season that focused in large part on logistics, Guskiewicz said. The next phase is to find the best technology for assessing head impact biomechanics and collect data that answers questions about potential rule changes that could improve player safety, along with improved equipment design and altered behavior.

The expansion of the sensor project still needs sign-off from the league and union, Guskiewicz said, adding that he couldn't reveal further details until that happens. It would be a good-faith gesture that both sides are serious about confronting the problem of concussions, which have become a dark cloud over the nation's most popular sport.

Congress questioned Commissioner Roger Goodell and NFLPA executive director DeMaurice Smith about the issue in 2009. Last August, the NFL reached a tentative $765 million class action settlement over concussion-related brain injuries - a deal that remains on hold because a federal judge has questioned whether there's enough money for 20,000 retired players.

Head accelerometers don't diagnose concussions. They assess frequency, location and magnitude of impact, providing more information for researchers and teaching tools for coaches, who can match video to data and encourage high-risk players to change the way they play.

"We've done a lot of validation work over the past 18 to 24 months using some of these devices," said Guskiewicz, who has been a member of the NFL's Head, Neck and Spine Committee and the NFL Players Association's Mackey-White Committee since 2010.

"It's really important that we know what the information is telling us and how to interpret it and how we can provide meaningful data back to the player, the athletic trainer or the team physician, the strength and conditioning coach, whoever that may be."

Last year, only the research committee had access to the data, Guskiewicz said. Once the program goes live, participating players would be able to sign consent forms allowing others to access it, creating the possibility a team doctor someday may have real-time data that prompts him to remove a player from a game - something the UNC football program already can do.

That figures to raise concerns from some NFL players and agents about negative data being used against them, particularly when it comes time to negotiate a contract. But many NFL teams already are beginning to collect advanced data on their own, with help from two Australian companies that specialize in athlete analytics and tracking technology.

Catapult Sports' roster of subscribing NFL teams has grown from six less than a year ago to 13, with several others in negotiations, according to Boden Westover, the company's media and marketing manager. Last season, the Seattle Seahawks were the first team to subscribe to GPSports Systems, which has signed two more teams since Seattle won the Super Bowl in February.

Each company manufactures a GPS tracking device that can measure a wide variety of indicators about a player's workload and includes an accelerometer, though the use of the accelerometer is limited when it comes to assessing collisions because the NFL doesn't allow the devices to be used in games.

"We want to give them context to the development of the athlete," said Gary McCoy, Catapult's senior applied sports scientist. "Our number one job is to reduce injury. If we can do that - and we've shown that we can do that with this data - all of a sudden you could save a career or you could save a season, just by offsetting a simple hamstring injury."

The Jacksonville Jaguars were the first NFL team to subscribe to Catapult in 2012, not long after Florida State University did it and raved about the results. The U.S. market "seemed to be a sleeping giant for a long time," said Damien Hawes, GPSports' international sales manager. "It was really, really resistant to change or embracing this type of technology," which has been used widely in rugby and soccer leagues for years.

Like the Catapult and GPSports devices, the devices approved by the NFL and NFLPA for the pilot program run off radio frequency. It wouldn't be a surprise if the league collects and provides teams with expanded player-tracking data in games somewhere down the line, though that's not the focus at this stage.

Guskiewicz said he's "thrilled" teams are finally buying in to the value of applied sports science. The collaborative effort between the NFL and the union to gather head impact data has taken time as well, too, in large part to ensure everyone feels comfortable it can be obtained unobtrusively and securely - and that it's worth the effort.

"I personally believe that there is valuable information to be gained for a player to learn how to perhaps modify his behavior, to track the way in which he's leading with his head possibly or positioning his body on a certain play type that could help protect him," Guskiewicz said.

"So, we just sort of have to go through this in a methodical approach to work on the feasibility. This year, I hope that we're able to move forward with answering some of the questions that we have around potential rules changes, and then the following year, who knows?"